But since early April the hospital has begun offering the surgery on an emergency basis. That means some heart attack patients will be able to get treatment sooner, minimizing the damage to their hearts and improving their chances for recovery.

And the cardiologists at Melrose-Wakefield - all of whom have been performing the surgery for eight or more years in other hospitals - hope to offer it soon on a non-emergency basis as well.

Currently, state law prevents Mel-Wak doctors from performing the operation on a routine basis.

Doctors perform angioplasty on patients who have a blockage in an artery. Surgeons insert a metal tube, called a stent, into the artery, and expand it, forcing the artery to open wider, which allows the blood to flow.

Only about 4 percent of heart attacks are the type that DiMarino had, said cardiologist Laurence Conway, one of the Melrose-Wakefield team, but the success rate for angioplasty in those patients is 97 percent.

Time is of the essence, said Melrose-Wakefield cardiologist Carl Turrasini, another member of the team. The mortality rate drops by 30 percent if doctors can open up the artery in less than two hours, and by half if doctors can do it in less than an hour. The Melrose-Wakefield team's goal is to open every patient's arteries within two hours.

When he set out to play golf on April 19, Patriot's Day, DiMarino had no idea that Melrose-Wakefield Hospital had begun offering emergency angioplasty - or that doctors there were just then operating on their first patient. "I was in the parking lot of the golf course waiting for my buddies to show up, and I started sweating and my legs felt a little wobbly," he said. When he began having chest pains, DiMarino went straight to Melrose-Wakefield Hospital, where the emergency room staff quickly determined he would need an angioplasty. As it happened, Conway and Turrasini were just finishing the surgery on the other patient.

"I can remember saying 'Am I dying?' and they said 'You are having a heart attack, and this is what we are going to do,'" said DiMarino. "Before I knew it, I was prepped and in the cardiac catheterization lab."

The surgeons injected dye into DiMarino's artery and located the blockage, then inserted a balloon into the artery to open it up and inserted the metal tube, which expands under pressure to hold the artery open. Within 90 minutes, DiMarino was in the recovery room.

That's a huge improvement over taking patients to Boston, Turrasini said. "We tracked door to balloon times, and when we had to send patients out to Mass General or the Lahey, the shortest door to balloon time we found in the last year was three hours. That's three hours of heart attack. That increases mortality, muscle loss, length of stay."

Conway remembers accompanying one heart attack patient to Boston in an ambulance on the lower deck of I-93 during the evening rush hour. "He went into shock," he said. "Eventually I got him back, but that was the longest two-mile ride of my life."

Before offering the surgery, hospital staff studied how to deliver it most efficiently. "They have worked out all the bugs in the system: How to get doctors in quickly, how to get patients triaged in the emergency room quickly," Turrasini said.

DiMarino agreed. "Someone did their homework well when they set this up, because they were moving," he said. "Everyone had a job to do, and they were doing it. There wasn't any confusion." He also praised the staff for the personal attention he got. "You weren't treated like a number," he said. "The care, the consideration, was always there." Three days after his heart attack, DiMarino was discharged, and he is now taking exercise and nutrition classes at the hospital. Because he got surgery so quickly, he said, there is probably no permanent damage to his heart.

Emergency angioplasties are expensive, and the hospital must have a team on call at all times, so the procedure is not a money-maker for the hospital, Conway said. But that's not the point. "We do it because we think it's the right thing to do," he said. "These cases are very satisfying."